photo: Todd Woody

Green Wombat has been in transition so I’m a bit behind on posting. In case you missed it, in the Sunday New York Times on May 9, I wrote a profile of David Gelbaum, one of the nation’s biggest — and until now — most reclusive green technology investors and environmental philanthropists:

AMID the $6 million homes perched on a beachfront cliff in this conservative Southern California enclave, the seven-year-old Honda Civic hybrid with the Obama bumper sticker is the giveaway.

It’s not the usual drive of choice for wealthy former hedge fund managers like David Gelbaum. Then again, there’s not much that is business as usual about Mr. Gelbaum, an intensely private person who happens to be one of the nation’s largest — and largely unknown — green technology investors and environmental philanthropists.

Mr. Gelbaum has invested $500 million in clean-tech companies since 2002 through his Quercus Trust, amassing a portfolio of some 40 businesses involved in nearly every aspect of the emerging green economy, be it renewable energy, the smart electric grid, sustainable agriculture, electric cars or biological remediation of oil spills. He has poured almost as much into environmental causes.

“I think his impact on green technology is huge,” says Bill Gross, the serial technology entrepreneur and founder of eSolar, a solar power start-up in which Mr. Gelbaum has invested. “He is supporting bolder and riskier bets, and he’s doing it from a different filter than a traditional venture capitalist, and I think that makes a wider opportunity for success.”

In this economic downturn, many venture capitalists have grown cautious about putting money into what Vinod Khosla, the prominent Silicon Valley green tech investor, calls “science experiments.” But Quercus Trust is still taking chances on blue-sky start-ups pursuing technological breakthroughs.

Working outside the clubby venture capital network, Mr. Gelbaum has, until recently, maintained an obsessively low profile. In Silicon Valley, he remains something of an unknown. Associates say his near-invisibility is owed to a genuine modesty and concerns over the security of his family because of his wealth. Recipients of his philanthropy, for instance, signed confidentiality agreements that forbade mention of his name.

Mr. Gelbaum says he decided to break his long silence upon becoming chief executive in February of Entech Solar, one of his portfolio companies that is publicly traded. “This is what’s best for the company,” he says, pointing out that Entech benefits if he maintains a more public profile.

It is too early to predict whether Mr. Gelbaum’s big green bets will pay off. But he’s been capitalizing on two trends: the rapid decline in the price of photovoltaic power, and a focus on cutting capital costs as solar power competition with China intensifies.

His environmental philanthropy also gives him an influence beyond laboratories and boardrooms. He has given $200 million to the Sierra Club and $250 million to the Wildlands Conservancy, a land trust he co-founded that has acquired and preserved 1,200 square miles of land in California, including more than a half million acres of the Mojave Desert.

photo: eSolar

Last week Green Wombat wrote about how solar power plant developer eSolar may avoid conflicts over endangered species by building its solar farms on privately owned agricultural land rather than in desert areas home to a variety of protected wildlife.

At the opening ceremony of eSolar’s Sierra demonstration power plant outside Los Angeles on Aug. 5, Wildlands Conservancy executive director David Myers gave a speech praising the Pasadena company for not building power plants in fragile desert ecosystems while criticizing competitors. The Wildlands Consevancy, a Southern California non-profit, has spent hundreds of millions of dollars buying up and preserving broad swaths of the Mojave Desert.

photo: eSolar

eSolar on Wednesday fired up its five-megawatt Sierra “power tower” solar farm outside Los Angeles during an opening ceremony that featured such green tech luminaries as Google.org climate change director Dan Reicher and Dan Kammen of the University of California at Berkeley.

But the speaker that caught my eye was environmentalist David Myers, executive director of the Wildlands Conservancy, a Southern California non-profit that is working with California Senator Dianne Feinstein to put hundreds of thousands of acres of the Mojave Desert off limits to industrial-scale solar power plants.

“By siting their project on disturbed lands, eSolar has avoided degrading treasured public lands and core areas of biodiversity,” said Myers. “This is an important distinction from the solar firms that propose to industrialize 600,000 acres of pristine California desert lands belonging to the American people.”

I’ve written extensively on Green Wombat and Grist about eSolar’s technology and CEO Bill Gross’ vision of a software-driven solar revolution that taps computing power to drive down renewable energy costs. (Google-backed (GOOG) eSolar has a partnership with energy producer NRG (NRG) to build power plants for Southern California Edison (EIX), PG&E (PCG) and other utilities.)

But eSolar’s strategy of building relatively small-scale modular solar farms on privately owned agricultural land is also allowing it to avoid — so far — fights over endangered species that have slowed big solar power plants planned for federally owned land in the Mojave Desert.

While Myers was praising eSolar at the Sierra ceremony, his environmental group, as I wrote in Wednesday’s New York Times, has been raising issues about the impact of Tessera Solar’s planned 8,230-acre, 850-megawatt power plant on such Mojave species as the desert tortoise, Mojave fringe-toed lizard and Nelson’s bighorn sheep.

Meanwhile, Defenders of Wildlife, a local chapter of the Sierra Club and other national and grassroots environmental groups are worried about the impact of BrightSource Energy’s 400-megawatt Ivanpah solar farm on the imperiled desert tortoise. The Sierra Club chapter recently proposed that BrightSource move the solar power plant to avoid disturbing habitat currently occupied by desert tortoises.

eSolar has spent $30 million acquiring previously disturbed ag land — mostly in California. While that should speed development of its solar farms as it won’t need federal approval to build, there’s no guarantee, of course, that the Pasadena, Calif.-based startup won’t also run into critter problems.

Just ask Ausra, the Silicon Valley solar company that’s building a 177-megawatt power plant on ag land in San Luis Obispo County on California’s central coast. That project has been bogged down in disputes over the solar farm’s consequences for a plethora of species and the cumulative impact of two other solar power plants planned for the same area that First Solar (FSLR) and SunPower (SPWR) want to build.

Still, eSolar’s focus on location, location, location could pay off. While the five-megawatt Sierra demonstration plant is a small project, the fact that company was able to get it built in a year is no doubt a competitive advantage.

“This plant delivers the lowest-cost solar electricity in history,” said Gross, the founder of tech incubator Idealab, at the ceremony in the L.A. ex-urb of Lancaster. “We currently compete with natural gas and as we continue to drive down the cost, we will even compete with coal.”

And if eSolar continues to carefully select sites for its solar farms it won’t have to worry about environmentalists like David Myers of the Wildlands Conservancy.

“You can see why the entire environmental community is so excited about a firm that’s model is to use disturbed lands,” said Myers after slamming an unnamed eSolar competitor for trying to build a solar farm in what he described as a fragile desert ecoystem. “We can’t say enough great things about eSolar.”

With that, Gross walked over to a computer, pressed a button and 24,000 mirrors began to focus sunlight on two water-filled boilers sitting atop two towers. As the intense heat vaporized the water, steam flowed to a power block to drive an electricity generating turbine.

About Green Wombat

Green Wombat is written by
Todd Woody, a veteran environmental journalist based in California who writes for The New York Times, the Los Angeles Times, Grist and Yale e360. He's one of the few people on the planet who have held a northern hairy-nosed wombat in the wild.

Todd formerly was a senior editor at Fortune magazine, an assistant managing editor at Business 2.0 magazine and the business editor of the San Jose Mercury News.